U.S. patent application number 13/628030 was filed with the patent office on 2014-03-27 for temperature-controlled power supply system and method.
This patent application is currently assigned to ENERGY PASS INCORPORATION. The applicant listed for this patent is ENERGY PASS INCORPORATION. Invention is credited to Chao-Hsuan Liu, Ying-Che Lo, Hsueh-Wen Tseng, Chia-Hsieh Wu.
Application Number | 20140084848 13/628030 |
Document ID | / |
Family ID | 50338201 |
Filed Date | 2014-03-27 |
United States Patent
Application |
20140084848 |
Kind Code |
A1 |
Liu; Chao-Hsuan ; et
al. |
March 27, 2014 |
Temperature-Controlled Power Supply System and Method
Abstract
A temperature-controlled power supply system is disclosed. The
temperature-controlled power supply system comprises a power
source, for supplying input power; a rechargeable battery module,
for receiving the input power for power storage; a charging unit,
coupled between the power source and the rechargeable battery
module, for charging the rechargeable battery module with the input
power; a temperature sensing unit, coupled to the rechargeable
battery module, for sensing a temperature of the rechargeable
battery module; and a current control unit, coupled to the
temperature sensing unit and the charging unit, for controlling a
current for charging the rechargeable battery module according to
the temperature of the rechargeable battery module.
Inventors: |
Liu; Chao-Hsuan; (New Taipei
City, TW) ; Tseng; Hsueh-Wen; (Hsinchu County,
TW) ; Wu; Chia-Hsieh; (Changhua County, TW) ;
Lo; Ying-Che; (Tainan City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ENERGY PASS INCORPORATION |
Hsinchu City |
|
TW |
|
|
Assignee: |
ENERGY PASS INCORPORATION
Hsinchu City
TW
|
Family ID: |
50338201 |
Appl. No.: |
13/628030 |
Filed: |
September 26, 2012 |
Current U.S.
Class: |
320/107 ;
320/150; 323/234 |
Current CPC
Class: |
H02J 7/007 20130101;
H02J 7/007192 20200101; H02J 7/007194 20200101 |
Class at
Publication: |
320/107 ;
320/150; 323/234 |
International
Class: |
G05F 1/10 20060101
G05F001/10; H02J 7/00 20060101 H02J007/00 |
Claims
1. A temperature-controlled power supply system, comprising: a
power source, for supplying input power; a rechargeable battery
module, for receiving the input power for power storage; a charging
unit, coupled between the power source and the rechargeable battery
module, for charging the rechargeable battery module with the input
power; a temperature sensing unit, coupled to the rechargeable
battery module, for sensing a temperature of the rechargeable
battery module; and a current control unit, coupled to the
temperature sensing unit and the charging unit, for controlling a
current for charging the rechargeable battery module according to
the temperature of the rechargeable battery module.
2. The power supply system of claim 1, wherein the temperature
sensing unit comprises a resistor of which a resistance value
varies with a variation of ambient temperature.
3. The power supply system of claim 1, wherein the current control
unit maintains the temperature of the rechargeable battery module
at a predefined value when the rechargeable battery module is under
charging, to control the current for charging the rechargeable
battery module according to the temperature of the rechargeable
battery module.
4. The power supply system of claim 1, wherein when the temperature
of the rechargeable battery module tends to increase, the charging
unit reduces the current for charging the rechargeable battery
module.
5. The power supply system of claim 1, wherein when the temperature
of the rechargeable battery module tends to decrease, the charging
unit increases the current for charging the rechargeable battery
module.
6. A temperature-controlled power supply method, comprising:
supplying input power; charging a rechargeable battery module with
the input power; sensing a temperature of the rechargeable battery
module; and controlling a current for charging the rechargeable
battery module according to the temperature of the rechargeable
battery module.
7. The method of claim 6, wherein a resistor of which a resistance
value varies with a variation of ambient temperature is utilized
for sensing the temperature of the rechargeable battery module.
8. The method of claim 6, wherein controlling the current for
charging the rechargeable battery module according to the
temperature of the rechargeable battery module comprises
maintaining the temperature of the rechargeable battery module at a
predefined value when the rechargeable battery module is under
charging.
9. The method of claim 6, wherein when the temperature of the
rechargeable battery module tends to increase, the current for
charging the rechargeable battery module is reduced.
10. The method of claim 6, wherein when the temperature of the
rechargeable battery module tends to decrease, the current for
charging the rechargeable battery module is increased.
11. A temperature-controlled power supply system, comprising: a
power source, for supplying input power; a load unit, for receiving
the input power; a temperature sensing unit, coupled to the load
unit, for sensing a temperature of the load unit; and a current
control unit, coupled to the temperature sensing unit and the power
source, for controlling a current for providing the load unit
according to the temperature of the load unit.
12. The power supply system of claim 11, wherein the temperature
sensing unit comprises a resistor of which a resistance value
varies with a variation of ambient temperature.
13. The power supply system of claim 11, wherein the current
control unit maintains the temperature of the load unit at a
predefined value when the load unit is receiving the input power,
to control the current for providing the load unit according to the
temperature of the load unit.
14. The power supply system of claim 11, wherein when the
temperature of the load unit tends to increase, the power source
reduces the current for providing the load unit.
15. The power supply system of claim 11, wherein when the
temperature of the load unit tends to decrease, the power source
increases the current for providing the load unit.
16. A temperature-controlled power supply method, comprising:
supplying input power to a load unit; sensing a temperature of the
load unit; and controlling a current for providing the load unit
according to the temperature of the load unit.
17. The method of claim 16, wherein a resistor of which a
resistance value varies with a variation of ambient temperature is
utilized for sensing the temperature of the load unit.
18. The method of claim 16, wherein controlling the current for
providing the load unit according to the temperature of the load
unit comprises maintaining the temperature of the load unit at a
predefined value when the load unit is receiving the input
power.
19. The method of claim 16, wherein when the temperature of the
load unit tends to increase, the current for providing the load
unit is reduced.
20. The method of claim 16, wherein when the temperature of the
load unit tends to decrease, the current for providing the load
unit is increased.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a temperature-controlled
power supply system and method, and more particularly, to a
temperature-controlled power supply system and method capable of
maintaining a temperature of a rechargeable battery at a predefined
value when the rechargeable battery is under charging.
[0003] 2. Description of the Prior Art
[0004] With the popularization of portable devices, power supply
systems with high sustainability and high efficiency are always
required. Therefore, high-efficiency rechargeable battery systems
are widely utilized in power supply systems. In general, a
rechargeable battery is first charged by a power source to store
electricity. When a portable device is equipped with the
rechargeable battery and turned on, the rechargeable battery starts
to supply power to the portable device.
[0005] Please refer to FIG. 1, which is a waveform diagram of
charging voltage and current of a conventional charging process of
a rechargeable battery. In general, the charging process can be
classified into three modes: a pre-charge mode M1, a constant
current mode M2, and a constant voltage mode M3. As shown in FIG.
1, if the initial voltage of the rechargeable battery is smaller
than a pre-charge threshold voltage V.sub.LOWV, the charging
process falls in the pre-charge mode M1. In the pre-charge mode M1,
the rechargeable battery is charged with a lower current. Since the
voltage of the rechargeable battery is smaller than the pre-charge
threshold voltage V.sub.LOWV, the stored electricity of the
rechargeable battery is near empty. At this moment, an inrush
current or even a larger charging current will reduce the life of
the rechargeable battery. After the voltage of the rechargeable
battery is greater than the pre-charge threshold voltage
V.sub.LOWV, the charging process enters the constant current mode
M2, i.e. the fast charge mode, and the power source starts to
charge the rechargeable battery with a normal current, which is
much greater than the current in the pre-charge mode M1. In the
constant current mode M2, the charging current remains at a
regulation current I.sub.REG and the voltage of the rechargeable
battery keeps increasing. The regulation current I.sub.REG is a
current regulated for charging the rechargeable battery according
to power efficiency or life sustainability of the rechargeable
battery.
[0006] After the voltage of the rechargeable battery increases to a
regulation voltage V.sub.REG, the charging process enters the
constant voltage mode M3, and the voltage remains at the regulation
voltage V.sub.REG and the charging current starts to decrease.
After the charging current falls to a termination current
I.sub.TERM, the electricity stored in the rechargeable battery is
near full and the charging process terminates.
[0007] As can be seen, in the constant current mode M2, the
regulation current I.sub.REG is regulated for charging the
rechargeable battery according to power efficiency or life
sustainability of the rechargeable battery. However, a rechargeable
battery may be unavoidably getting old. If the regulation current
I.sub.REG is most adaptive for a newer rechargeable battery, it may
not be still adaptive for an older rechargeable battery. One of the
main reasons comes from temperature. For example, temperature may
rise when a rechargeable battery is under charging due to the
imperfection of power conversion. When the rechargeable battery
becomes aging, the charging efficiency may be reduced, which may
cause a higher temperature. If the temperature is too high and
touches an over-temperature protection level, charging may be
stopped, and restarted until the temperature falls to another
level. As a result, life of the rechargeable battery may be reduced
due to high temperature, and frequent stop and restart of charging
may reduce the charging efficiency much more. Thus, there is a need
for improvement of the prior art.
SUMMARY OF THE INVENTION
[0008] It is therefore an objective of the present invention to
provide a temperature-controlled power supply system and method
capable of maintaining a temperature of a rechargeable battery at a
predefined value when the rechargeable battery is under
charging.
[0009] The present invention discloses a temperature-controlled
power supply system, which comprises a power source for supplying
input power, a rechargeable battery module for receiving the input
power for power storage, a charging unit, coupled between the power
source and the rechargeable battery module, for charging the
rechargeable battery module with the input power, a temperature
sensing unit, coupled to the rechargeable battery module, for
sensing a temperature of the rechargeable battery module, and a
current control unit, coupled to the temperature sensing unit and
the charging unit, for controlling a current for charging the
rechargeable battery module according to the temperature of the
rechargeable battery module.
[0010] The present invention further discloses a
temperature-controlled power supply method, which comprises
supplying input power, charging a rechargeable battery module with
the input power, sensing a temperature of the rechargeable battery
module, and controlling a current for charging the rechargeable
battery module according to the temperature of the rechargeable
battery module.
[0011] The present invention further discloses a
temperature-controlled power supply system, which comprises a power
source for supplying input power, a load unit for receiving the
input power, a temperature sensing unit, coupled to the load unit,
for sensing a temperature of the load unit, and a current control
unit, coupled to the temperature sensing unit and the power source,
for controlling a current for providing the load unit according to
the temperature of the load unit.
[0012] The present invention further discloses a
temperature-controlled power supply method, which comprises
supplying input power to a load unit, sensing a temperature of the
load unit, and controlling a current for providing the load unit
according to the temperature of the load unit.
[0013] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a waveform diagram of the charging voltage and
current of a conventional charging process.
[0015] FIG. 2 is a schematic diagram of a temperature-controlled
power supply system according to an embodiment of the present
invention.
[0016] FIG. 3 is a waveform diagram of the charging voltage and
current in accordance with the temperature of the rechargeable
battery module in the temperature-controlled power supply system
according to an embodiment of the present invention.
[0017] FIG. 4 is a waveform diagram of the charging voltage and
current in accordance with the temperature of several rechargeable
batteries according to an embodiment of the present invention.
[0018] FIG. 5 is a schematic diagram of a general electronic device
embodied with a temperature-controlled power supply system
according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0019] Please refer to FIG. 2, which is a schematic diagram of a
temperature-controlled power supply system 20 according to an
embodiment of the present invention. As shown in FIG. 2, the
temperature-controlled power supply system 20 includes a power
source 202, a rechargeable battery module 204, a charging unit 206,
a temperature sensing unit 208, and a current control unit 210. The
power source 202 supplies input power Vin to the charging unit 206,
and may also supply power to the whole temperature-controlled power
supply system 20. The rechargeable battery module 204 is utilized
for storing the input power Vin. The charging unit 206, coupled
between the power source 202 and the rechargeable battery module
204, is utilized for charging the rechargeable battery module with
the input power Vin. The charging unit 204 may also be implemented
in the power source 202, and is not limited herein. The temperature
sensing unit 208, coupled to the rechargeable battery module 204,
is utilized for sensing a temperature of the rechargeable battery
module 204. The temperature sensing unit 208 may sense the ambient
temperature of the rechargeable battery module 204 or sense the
temperature inside the rechargeable battery module 204. In general,
the temperature sensing unit 208 may be implemented with a resistor
of which a resistance value varies with a variation of ambient
temperature, and is not limited herein. The current control unit
210, coupled to the temperature sensing unit 208 and the charging
unit 206, is utilized for controlling a current for charging the
rechargeable battery module 204 according to the temperature of the
rechargeable battery module 204.
[0020] Please note that, the temperature-controlled power supply
system 20 may charge the rechargeable battery module 204 in a
constant temperature manner different from the conventional
constant current manner. As shown in FIG. 1, in the constant
current mode M2, the charging current remains at a regulation
current I.sub.REG, which is a current regulated for charging the
rechargeable battery according to power efficiency or life
sustainability of the rechargeable battery. In other words, if a
rechargeable battery is charged with the regulation current
I.sub.REG, power efficiency or life sustainability of the
rechargeable battery may be optimized when the rechargeable battery
is charged with the regulation current I.sub.REG.
[0021] As mentioned above, the regulation current I.sub.REG most
adaptive for a newer rechargeable battery may not be still adaptive
for an older rechargeable battery. One of the main reasons comes
from temperature. Therefore, to deal with the temperature, the
embodiment of the present invention senses the temperature of the
rechargeable battery module 204 with the temperature sensing unit
208, and then controls the charging current to charge the
rechargeable battery module 204 according to the sensed
temperature, so as to keep the temperature of the temperature
sensing unit 208 at or near a predefined value. Therefore, a
constant temperature charging system is built up, and this constant
temperature charging system is adaptive for all rechargeable
batteries.
[0022] Please refer to FIG. 3, which is a waveform diagram of the
charging voltage and current in accordance with the temperature of
the rechargeable battery module 204 in the temperature-controlled
power supply system 20 according to an embodiment of the present
invention. As shown in FIG. 3, when the power source 202 is turned
on and starts to supply power, if the initial voltage of the
rechargeable battery module 204 is smaller than a pre-charge
threshold voltage V.sub.LOWV, the charging process falls in the
pre-charge mode M1. At this moment, the temperature of the
rechargeable battery module 204 may increase a little since the
charging current in the pre-charge mode M1 is small. After the
voltage of the rechargeable battery is greater than the pre-charge
threshold voltage V.sub.LOWV, the charging process enters the
constant current mode M2, i.e. the fast charge mode, and the power
source starts to charge the rechargeable battery with a normal
current, which is much greater than the charging current in the
pre-charge mode M1. At this moment, the temperature of the
rechargeable battery module 204 may increase much more. When the
temperature of the rechargeable battery module 204 increases to a
regulation temperature T.sub.REG, the charging process enters a
constant temperature mode M2', which is different from the
conventional charging process. In the constant temperature mode
M2', the temperature of the rechargeable battery module 204
maintains at the regulation temperature T.sub.REG, and the voltage
of the rechargeable battery module 204 may still increase. The
charging current may fall since if the charging current keeps at
the regulation current I.sub.REG, the temperature of the
rechargeable battery module 204 may still increase. Therefore, the
charging current should fall in order to maintain the temperature
of the rechargeable battery module 204 at the regulation
temperature T.sub.REG. After the voltage of the rechargeable
battery increases to the regulation voltage V.sub.REG, the charging
process enters the constant voltage mode M3. The voltage remains at
the regulation voltage V.sub.REG, and the charging current and the
temperature of the rechargeable battery module 204 both starts to
decrease. After the charging current falls to a termination current
I.sub.TERM, the electricity stored in the rechargeable battery is
near full and the charging process terminates.
[0023] In the constant temperature mode M2', the temperature of the
rechargeable battery module 204 may tend to increase or decrease
due to interference from other circuits or ambient environments. If
the temperature of the rechargeable battery module 204 tends to
increase, the temperature sensing unit 208 receives the increasing
temperature and instructs the current control unit 210 to reduce
the charging current for the charging unit 206 to charge the
rechargeable battery module 204. On the other hand, if the
temperature of the rechargeable battery module 204 tends to
decrease, the temperature sensing unit 208 receives the decreasing
temperature and instructs the current control unit 210 to increase
the charging current for the charging unit 206 to charge the
rechargeable battery module 204. In some cases, it is difficult to
make the temperature of the rechargeable battery module 204
maintain as a constant. However, the charging current can still be
controlled by sensing the temperature. One feasible method is to
classify the temperature of the rechargeable battery module 204 to
several levels and define several charging current values
corresponding to those temperature levels. In general, if the
temperature falls in a lower level, the current control unit 210
may control the charging current to be a higher current value; if
the temperature falls in a high level, the current control unit 210
may control the charging current to be a lower current value. In
some cases, the voltage of the rechargeable battery module 204
touches the regulation voltage V.sub.REG before the temperature of
the rechargeable battery module 204 touches the regulation
temperature T.sub.REG. At this moment, the charging process omits
the constant temperature mode M2' and directly proceeds the
constant voltage mode M3.
[0024] In general, the internal resistance of an older rechargeable
battery may be greater than that of a newer rechargeable battery.
Power efficiency may be lower in the older rechargeable battery,
and more power may be wasted, which may cause the temperature of
the older rechargeable battery to increase faster than the newer
rechargeable battery. Therefore, the older the rechargeable battery
is, the earlier the constant temperature mode M2' occurs. Please
refer to FIG. 4, which is a waveform diagram of the charging
voltage and current in accordance with the temperature of several
rechargeable batteries according to an embodiment of the present
invention. As shown in FIG. 4, with the older rechargeable battery,
the temperature arrives the regulation temperature T.sub.REG faster
and the constant temperature mode M2' starts earlier. On the other
hand, with the newer rechargeable battery, the temperature arrives
the regulation temperature T.sub.REG slower and the constant
temperature mode M2' starts later. As a result, by properly setting
the regulation current T.sub.REG and the regulation temperature
T.sub.REG, a temperature-controlled power supply system adaptive
for all rechargeable batteries can be achieved.
[0025] Please note that, the regulation temperature T.sub.REG has
to be lower than an over-temperature protection threshold and
preferably with a margin. Actually, the regulation temperature
T.sub.REG is preferably set to be a temperature of the rechargeable
battery where power efficiency or life sustainability of the
rechargeable battery is optimized.
[0026] Noticeably, the spirit of the present invention is to
provide a temperature-controlled power supply system. Those skilled
in the art can make modifications and alterations accordingly. For
example, in addition to a charging system, all kinds of electronic
system which needs power supply can be implemented with
temperature-control. Please refer to FIG. 5, which illustrates a
general electronic device embodied with a temperature-controlled
power supply system 50. The temperature-controlled power supply
system 50 includes a power source 502, a load unit 504, a
temperature sensing unit 508, and a current control unit 510. The
power source 502, the temperature sensing unit 508, and the current
control unit 510 are similar to the power source 202, the
temperature sensing unit 208, and the current control unit 210,
respectively. Distinct from the temperature-controlled power supply
system 20, the load unit 504 is considered to replace the
rechargeable battery module 204, and the charging unit 206 is
considered as a current supply unit and implemented in the power
source 502. The load unit 504 can be any kinds of loads in an
electronic device. The detailed description of the
temperature-controlled method can be referred to the above
description, and will not be narrated hereinafter.
[0027] In the prior art, the conventional charging process charges
with a constant current even if the temperature keeps increasing.
If the temperature touches an over-temperature protection level,
charging may be stopped, and restarted until the temperature falls
to another level. As a result, life of the rechargeable battery may
be reduced due to high temperature, and frequent stop and restart
of charging may reduce the charging efficiency. In comparison, the
present invention is capable of maintaining a temperature of a
rechargeable battery at a predefined value when the rechargeable
battery is under charging, and can prevent the temperature of the
rechargeable battery from touching the over-temperature protection
level. Therefore, power efficiency and life sustainability of the
rechargeable battery can be optimized.
[0028] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *